1. Field of the Invention
The present invention relates to a method for igniting a burner, especially a burner that is used in industrial furnaces.
2. Description of the Related Art
There exist burners of various kinds, having in common that a gaseous fuel and a gaseous oxidant are introduced near or at a distance from each other into a combustion zone within a furnace. The gases are usually introduced through lances in a burner head.
For safety reasons, a burner needs to be monitored with respect to whether a flame is present during operation. Such monitoring is usually carried out by the use of a UV sensor, which is a sensor that is sensitive to and that detects ultraviolet radiation. The sensor is usually mounted in the burner in such a way that the sensor can detect a part of an existing flame.
Ignition of the fuel/oxidant mixture normally takes place by means of a spark plug at the outlet or outlets of the burner, to emit a spark for igniting the fuel/oxidant mixture. An electrode is commonly mounted inside a ceramic tube that extends up to the surface of the burner head that faces the furnace interior space. The ceramic tube has a relatively low strength and is therefore easily broken. The tube can also crack because of thermal stresses.
In addition to the problems noted above relative to the ceramic tube, it has developed that it is relatively difficult to obtain a correct electric arc. During furnace operation the spark plug often gets clogged, and as a result it cannot give off a sufficient spark for igniting the fuel/oxidant mixture.
Also, it is usual practice that the spark ignites a pilot flame, which in turn ignites the main flame. That arrangement increases the cost.
The present invention solves these problems by providing another way of igniting a burner.